FR2655683A1 - DEVICE FOR PERFORMING THE CUT-TAPPING RUNNING OF THREADED JUNCTIONS FOR ASSEMBLING TUBES. - Google Patents

Abstract

The device relates to the execution of at least one screwing-unscrewing cycle of threaded joints for assembling tubes with tightening at high torque to prevent subsequent damage to the threads. This device comprises two keys (1) each engaging on a component (51) of the junction in order to perform at least one screwing-unscrewing cycle. The gripping means of each key (1) comprise at least one movable jaw (40) sliding with a small clearance in a chamber (32) under the action of a pushing means (33) which applies it against the wall of component (51). The base material of this movable jaw has a resistance to plastic deformation lower than the stress to which it is subjected in order to distribute the pressure which it exerts. Application to the lapping of components of threaded joints for oil drilling tubes.

Description

The device and the method which are the subject of the invention relate to the

  break-in of threaded joints for tube assembly They concern in particular the components of the threaded joints (tool joints) which are reported by welding at the ends of the rods

  tubulars used for oil drilling.

  In use, these rods each having a male end

  and a female end undergo numerous tightening cycles.

  unscrewing with each tightening at high torque Experience has shown that, during the first cycles, despite the protection of the nets by suitable treatments, such as copper plating, zinc powder coating, or the like, these nets are particularly susceptible to be

  damaged, for example by jamming when screwing or unscrewing.

  To avoid these risks, it is common practice to perform, before putting into service of these tubular rods, a lapping with or without grease which consists of subjecting each of the threaded ends of each rod to at least one screw-unscrewing cycle, comprising locking at the end of screwing with application of a torque whose moment

  is preferably higher than those which will be applied in

  Experience shows that by doing this screwing

  At moderate rotational speeds and with the application of a progressive tightening torque, seizing and damage to the threads is prevented in service. In addition, the junction lock is locked with a moment torque greater than that used in practice. creates a kind of surface hardening at the threads and seal surfaces that reduces the subsequent risk of damage

  The results are obtained by performing several tightening cycles.

  unscrewing with precise control of torque moment and increasing

this one as and when.

  These operations are made difficult by the length of the tubular rods, about ten meters each Their alignment

  precise, usually horizontal, is not always easy to

  These rods may also have a slight curvature which may cause incorrect alignment of the male and female threads -2- with deterioration of the threads during screwing. Finally, the execution of successive cycles of screwing and unscrewing is accompanied by the formation of more or less deep impressions left by the jaws of the wrenches on the outer wall of the end zones of the rods In some cases, the pressure of the jaws deforms the ends of the rods

  tubular and can also cause the formation of cracks.

  It has been investigated the possibility of producing a device for lapping the threaded junctions of tubes, also called

  rods, by performing at least one tightening cycle.

  unscrewing which avoids the disadvantages of known methods

  which have just been described.

  avoid permanent deformation of the ends of the tubes,

  under the pressure exerted by the jaws of the wrenches

  also sought the possibility of eliminating the risk of local formation of cavities or crack initiation, under the action of the teeth of these jaws was also sought the possibility of achieving a tightening, at a fixed speed, the components of the junction threaded,

  with a blocking torque having a maximum

  It has also been investigated the possibility of simplifying the conditions for carrying out the screw-and-unscrewing cycles necessary for the lapping of the threaded joints, when these are of the component type.

  reported by welding to the ends of the tubes after machining.

  The device and the method which are the subject of the invention make it possible to achieve the desired results while avoiding the disadvantages

known devices.

  The device according to the invention makes it possible to perform the break-in

  screwing-unscrewing of the components of the threaded joints for assembling

  This lapping can be carried out while the components of these threaded joints are integral with the tubes to which they correspond. However, the components of these threaded joints, most often called "tool joints" are

  lapped, by means of the device according to the invention, before being

  welded to the ends of the tubes, also called tubular rods (rods), corresponding This device makes it possible to perform at least one screw-unscrewing cycle at each threaded junction that is honed It comprises two keys of clamping engagement one on the male component and the other on the female component of each junction Each of these keys comprises gripping means for gripping the outer wall of the component that corresponds to it and means of clamping of these gripping means on this outer wall At least one of these keys is connected to at least one means for driving in rotation about the axis of the threaded junction, making it possible to exert on the corresponding component a locking torque , at the end of screwing, of determined moment, then a release torque at the beginning of the unscrewing Advantageously, each of these keys is connected to at least one means for driving in rotation about the axis of the junction threaded, for exerting on the corresponding component a locking torque, at the end of screwing, determined moment, then a release torque at the beginning of the unscrewing In the case where there is only one key connected to a means training in

  rotation, the other key is held fixed.

  According to the invention the gripping means of each of these keys comprise at least one movable jaw able to slide, with a small clearance, in a chamber whose side walls surround it, under the action of a thrust means which bears on the rear wall of this jaw whose front wall has a profile adapted to that of the outer wall facing the component against which it comes to exert the necessary pressure This pressure is that which allows to apply to the component, by means of the key, a moment locking torque determined, then unlocking, without significant angular slip of the jaw with respect to the component Moreover, the base material of this movable jaw must have a resistance to plastic deformation less than the stress created in this bit by the thrust necessary for

  prevent slipping under the action of this moment.

  Preferably, this base material of this movable jaw is a solid organic polymer such as a plastic material, an elastomer, or a polymer combining the properties of a plastic material and an elastomer Advantageously, this organic polymer The solid is reinforced with yarns or fibers. Advantageously, it contains hard solid particles dispersed on the surface of the jaw opposite the component or in the mass of the jaw to increase the coefficient of friction between the surface of the jaw and the surface of the jaw. component These particles may for example be tungsten carbide grains The order of magnitude of the grain size

can be for example 1 mm.

  Preferably, the thrust means of the movable jaw is at least one jack whose head or push plate, in contact with the rear wall of the jaw, is engaged in the bottom of the chamber and slides inside the this with a small clearance along its side walls Preferably, the movable jaw cooperates with a fixed jaw, the two jaws lying on either side of the component of the threaded junction inside the chamber also preferably, the fixed jaw is made of a material having a resistance to plastic deformation less than the maximum stress at which it is

  subjected by the pressure exerted by the movable jaw on the component.

  This material is advantageously similar to that of the movable jaw.

  The means for rotating the key or each of the keys advantageously consists of an arm secured to said key, the arm being radial relative to the axis of the junction, the end of the arm being connected by a rod. at least one jack which makes it possible to turn the arm, in the direction of screwing or unscrewing, with a determined maximum angular amplitude which may for example be 600 The maximum torque moment exerted by the jack is at least equal

  at the moment of the blocking torque which it is necessary to carry out

  The cylinder is hydraulic and is hinged at one of its ends to the end of the key arm and at the other end to a point on the structure supporting the bearing around which the key

is articulated in rotation.

  The device comprises at least one means for indicating the moment of the

  torque exerted by the keys on the threaded junction This means of

  can be fed by a signal depending on the pressure exerted

  by the hydraulic fluid acting on a cylinder connected to an arm.

  When the angle c "formed between the radial arm of the key and the axis of the jack is variable as a function of the angular displacement of the arm, a signal correction means is preferably used so as to indicate directly the moment of the torque exerted by the key, according to the relation M = F sin O <R, M being the moment of the torque, F the force applied by the jack and R the radius of the key arm When two double-acting cylinders are used , each actuating an arm of a key, these two cylinders are advantageously arranged on the same side of the keys and advantageously fed in high pressure fluid only one cylinder at a time, so as to cause the displacement of the piston of this cylinder in the desired direction and a permanent connection is made between the orifice located at the other end of the cylinder chamber and the corresponding orifice of the other cylinder so as to cause

  the synchronized reverse movement of the piston thereof.

  To reverse the displacement of the pistons of the two cylinders it suffices to change the direction of circulation of the hydraulic fluid by supplying the second cylinder with high pressure fluid, the flow of this fluid occurring through the orifice of the first cylinder through which this high fluid

  pressure was first injected into this particular mode of feeding.

  tation of the cylinders, it is advantageous to use as a pressure source supplying the signal transmitted to the moment indicator of the torque exerted, a pressure taken on the connecting pipe

between the two cylinders.

  The invention also relates to a method for lapping threaded joints for assembling tubes, in which at least one screw-and-unscrewing cycle is performed on the components of this junction, whether or not integral with the tubular sections to which they correspond, method in which two keys are each engaged on a component and either the two keys are mobile or a key being

  fixed and the other mobile, the keys are driven by a relative motion.

  Tif in opposite direction to block or unblock the junction According to this method, it implements, to make the decision of each key on the component, at least one jaw housed in a chamber that surrounds it closely, when you submit to a constraint such as, considering

  of the material of which it is composed, its limit of resistance to deformation

  Plasticization is exceeded and this jaw exerts a pressure distributed over the surface of the component with which it is in contact. A second fixed jaw, housed in the same chamber and of which

  the material has characteristics similar to those of the movable jaw.

  It is also possible, in order to carry out the lapping method according to the invention, to use a plurality of movable jaws angularly distributed around the axis of each component of the threaded junction and pressurized each in a chamber. plastic flow of the jaws outside the chambers, it is necessary to minimize the clearance between the edges of the passage openings of these chambers and the outer surface of the components of the junction Similarly, in order to control this plastic flow, a material having a creep speed limited to a suitable value in the

operating conditions.

  The example and the figures below describe, in a nonlimiting manner, a particular embodiment of the device and the method which

are the subject of the invention.

  FIG. 1 is an overview, in perspective, of a mode of

  embodiment of the device according to the invention.

  Figure 2 is an elevational view of a key of the following device

the invention.

  FIG. 3 is a view of a threaded junction which is made on

  break-in by the method according to the invention.

  Figure 4 shows, in a schematic way, a particular mode of

  the actuators that actuate the arms of the device keys

according to the invention.

  FIG. 1 is an overview of an embodiment of the lapping device for tube joint components (tool joints) which is more particularly suitable for the types of tubes known as rods or rods used for oil drilling. . This device comprises two wrenches 1, 2 each provided with a hollow pin 3, 4, integral with the corresponding key, which is rotatably mounted in the bearing bore 5, 6 of a corresponding key support structure 7 8 Each key is provided with an arm 9 at the end 11, 12 of which is hingedly connected to one end of a drive cylinder 13, 14 The other end of this cylinder is attached articulated about axes of articulation 17, 18 to the lower part of the key support structure 7, 8 The two key support structures 7, 8 themselves rest on a common frame 19 through parts resilient bearing means such as 20, 21 (see FIG. 2) At rest, in the absence of stresses, the key support structures 7, 8 are wedged on the common frame 19 so that their bores 5, 6 have a common axis Xl Xl Under these conditions the two keys are located side by side, separated by a weak deviation that varies during tightening or loosening of both

  male and female components of a threaded junction The axial clearance requires

  saire is provided so that the hollow trunnions 3,4 can move -7 -

  axially of the corresponding quantity in the bores 5, 6.

  FIG. 2 is a side view, in elevation, of the key 1. A cutout 30 made in the side wall 31 of the chamber 32 of the key 1 reveals the movable jaws 40 and fixed 41 surrounding the component 51 of the threaded junction 50 (FIG. see FIG. 3) The walls of the chamber 32 are designed to withstand the pressure transmitted to them by the jaws 40, 41, when they exceed their limit of resistance to plastic deformation. This chamber 32 has an opening in which is engaged the thrust plate 33 which is pushed by the pistons 34 of two unidirectional cylinders 35 mounted side by side and exerting their thrust from bottom to top A small return cylinder 36 ensures the return of the plate 33 and is made visible by cutting 37 performed in one of the two support arms 38

  of the hinge 11 of the jack 13 The fixed upper jaw 41 is solid.

  darisé with the upper wall of the chamber 32 by at least one means

  such as the screw 42 The movable lower jaw 40 is solidly

  rised with the thrust plate 33 by suitable means not

  Each of these jaws has, at its commissioning, a bearing surface of cylindrical hollow shape, extending over a little less than 1800. The radius of these surfaces, before bearing on the component, is initial state, preferably a little weaker than that of the outer surface of the component on which the jaws will exert their thrust so that one makes a wedge effect when tightening on the component can for example achieve the jaws polyamide such as l'ERTALON (trademark of ERTA-NV Belgium) or

the NYLON.

  For the production of these jaws 40, 41, a plastic material is used.

  with a relatively high creep resistance, while maintaining sufficient ductility and having a coefficient of friction sufficiently high to transmit, without slipping, to the corresponding component, the torque exerted by the cylinder 13 is adjusted the clamping pressure exerted by the jaws 40, 41 under the action of the jacks 35 as a function of the moment of the tightening torque that is to be achieved In the case of the threaded junction 50 of axis X 2 -X 2, the components 51, 52 have Conical threads 53 (see FIG. 3) These are components intended to be attached by welding to the ends of the corresponding tubular rods. In most cases, pre-screwing is carried out at very low torque, before locking the welded joint. or not is introduced into the passage provided in the device, the inner diameters of the hollow journals 3, 4 as well as those of the openings centered on the axis X1-X1 of the walls such as 31 chambers such as e 32 being determined for this The openings of the walls of the chambers leave only a small clearance for the passage of the components Moreover each of them must exceed by its cylindrical part outside the rooms such as 32 in order to preserve this low clearance when the thrust of the jaws is brought to its maximum value As shown in Figures 1 and 4, it is advantageous to use a particular method of actuating cylinders which

drive the keys.

  According to this method, a high-pressure fluid supply means (not shown) is connected, by a distibutor means (not shown), to

  one of the two fluid introduction or exit orifices 60 or 61.

  The other orifice 61 or 60 is connected to the fluid return duct at the high pressure pump, not shown. The other two orifices 62, 63

  arranged at the ends of the cylinders adjacent to their axes of articulation.

  17, 18 on the frame 19 are interconnected by the channeling

  connection 64, on which is taken, by the pipe 65, the pressure signal which contributes to the operation of the torque moment indicator applied to the junction 50 It is seen that when the

  high pressure fluid enters through port 60, the keys are

  born by the jacks in the direction of the screwing (for a step to the right).

  In order to have the maximum stroke, the cylinders 13, 14 are first fed, without taking any keys on the component, through the orifice 61 in the unscrewing direction. The keys are then engaged on the components 51, 52 of FIG. the junction 50 by action of the pistons such as 34 jacks such as 35 on the movable jaws such as 40 and finally

  feeds the cylinders 13, 14 through the orifice 60 in the direction of screwing.

  The fluid pressure is adjusted at the inlet until the level of

  pressure in the connecting pipe 64 reaches the desired value.

  Note that we have a total angle of screwing of 1200,

  without exceeding for the arms of the keys an inclination of 30

  vertical port; the corresponding angle θ <being not less than 600 the sin oc, is not less than 0.866 Such a screwing angle is generally sufficient to obtain the high torque locking of such a pre-screwed junction Si c If the target moment for locking torque is reached, we see that it is easy, alternating the introduction of high-pressure fluid -9

  through the orifices 60, 61 to execute several unlocking cycles

  junction cage 50 It can be seen that the efforts exerted by the

  jacks, in particular at the joints 17, 18 are absorbed

  by the frame 19 thanks to the retaining bars 66, 67 secured to this frame and to the elastic bearing parts such as 20, 21 which

play the role of shock absorber.

  Many variations or modifications can be made to the device and method according to the invention which do not go beyond the scope thereof. In particular, although the example relates to threaded joints with conical threads not yet mounted on the rods. corresponding tubular it is obvious that the device and the method apply to all types of threaded conical or cylindrical junction for tubes, these junctions are or not secured

tubes that correspond to them.

-10-

Claims (11)

  1) Device for lapping threaded joints comprising a male component and a female component for assembly   of metal tubes, by performing at least one screwing cycle   unscrewing with attaining the blocking for a given moment of the tightening torque, this device comprising two keys each engaging a component and at least one of these keys being connected to a rotation drive means making it possible to reach, in the end of screwing, the determined moment of the locking torque characterized in that the   means for gripping each of these keys (1, 2) on the corresponding component.   laying material (51, 52) comprise at least one movable jaw (40), able to slide with a slight clearance in a chamber (32) whose side walls surround it, under the action of a thrust means (33) which abuts against the rear wall of this movable jaw whose front wall is applied to the outer wall of the component (51), the base material of this movable jaw being such that it has a lower resistance to plastic deformation to the stress to which it is subjected by the thrust means to prevent angular sliding of the jaw on the component under the action of the moment of the couple locking the junction (50).   2) Device according to claim 1 characterized in that each of the wrenches is connected to a rotational drive means to reach, at the end of screwing, the determined moment of the locking torque. 3) Device according to claim 1 or 2 characterized in that the   base material of the movable jaw (40) is a solid organic polymer.   4) Device according to claim 3 characterized in that the solid organic polymer is a plastic material, or an elastomer, or a polymer combining the properties of a plastic material and an elastomer.   Device according to Claim 3 or 4, characterized in that the solid organic polymer contains at least one additive in the form of fibers or discontinuous yarn.   6) Device according to claim 3 or 4 characterized in that the E i 265,568; 3   Solid organic polymer contains at least one additive in the form of solid particles to increase the coefficient of friction, these solid particles being dispersed either on the surface of the jaw in   look of the component is in the mass of the bit.   7) Device according to one of claims 1 to 6 characterized in that   that the thrust means of the movable jaw is at least one jack (35) whose thrust plate (33) is engaged in the chamber (32) with a small clearance and bears against the rear wall of the movable jaw (40).   8) Device according to one of claims 1 to 7 characterized in that   that the movable jaw (40) cooperates with a fixed jaw (41), one and the other being inside the same chamber (32), on either side of the component (51).   9) Device according to claim 8 characterized in that the base material of the fixed jaw (41) is similar to that of the movable jaw (40).   Device according to one of Claims 1 to 9, characterized   each key connected to a rotational drive means (1, 2) is integral with a radial arm (9, 10) with respect to the axis (X1-X1) of the threaded junction whose end is connected by a connection (11, 12) to at least one hydraulic cylinder (13, 14) which makes it possible to turn the arm in one direction or the other the moment of the torque exerted that can reach at least the moment of the locking torque of the junction (50) to be made.   11) Device according to one of claims 1 to 10 characterized in   it comprises means for indicating the torque moment exerted by the keys (1, 2) on the threaded junction (50) which receives a pressure signal of the hydraulic fluid acting on at least one jack (13, 14). ), a correction means being applied directly as a function of the sine of the angle "('formed by the axis of the jack with the radius of the arm   of the key to which it is connected.   12) Device according to one of claims 2 to 11 characterized in   two double-acting cylinders are operated each actuating an arm (9, 10) of a key (1, 2), the two cylinders having a permanent connection (64) between them, at one of their ends located   on the same side, the supply of high-pressure fluid being effected   killed at one of the other two ends chosen in the sense of   screwing or unscrewing the junction to be made.   13) Method for running-in threaded junctions for assembling tubes in which at least one screw-and-unscrewing cycle is performed on the components of this junction and in which two keys are each engaged on a component and at least one of these keys is driven in rotation to block or unblock the junction characterized in that to exert the taking of each key (1, 2) on the component (51, 52) which corresponds to it is implemented at least one jaw (40) housed in a room (32) which surrounds it closely and is subjected to a stress such that, given the material of which it is composed, its limit of resistance to plastic deformation is exceeded and it exerts a distributed pressure on the surface of the component (51) with which he is in contact with.   14) Method according to claim 13 characterized in that the two keys are rotated in opposite directions to block or unlock the junction.